An October 2011 search of New York City-based job listings found more than a dozen that explicitly required candidates to be employed, Manhattan Borough President Scott Stringer's office said. A broader review that year by the National Employment Law Project found 150 ads that were restricted to or aimed at people currently working.

As for why, experts say employers may think that unemployed applicants' skills have atrophied, that they lost their jobs because of their own shortcomings, or that they will jump at any job offer and then leave as soon as something better comes along.

But "'don't apply, don't even try' is the opposite of American values," New York City Council Speaker Christine Quinn said when the measure passed last month. She said Friday that she expects the City Council will override Mayor Michael Bloomberg's veto within a month.

Bloomberg called the measure a well-intended but misguided effort that would create more lawsuits than jobs.

"Hiring decisions frequently involve the exercise of independent, subjective judgment about a prospective employee's likely future performance," he said in a statement.

And unlike other characteristics that employers are generally banned from considering, such as an applicant's race, religion or gender, "the circumstances surrounding a person's unemployment status may, in certain situations, be relevant to employers when selecting qualified employees," he said.

Business groups say that no-unemployed-applicants-need-apply ads represent a tiny fraction of the millions of job openings nationwide each year.

One 2011 listing that got city lawmakers' attention â¿¿ it required that applicants for an opening as a New York legal secretary "must be currently employed" â¿¿ was mistakenly written that way, said William Alcott, a lawyer for the firm that posted it, McGuireWoods LLP.

"It was not our policy then and isn't our policy now," he said this week.

Like other measures that have passed, the New York City one would ban help-wanted ads that say unemployed applicants won't qualify. It would also more generally prohibit employers from refusing to hire candidates because they are out of work.

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